In the case of semiconductor laser diodes based on nitridic compound semiconductors, the efficiency of the generation of radiation usually decreases with increasing wavelength. This makes it more difficult to generate radiation in the green spectral range. Hitherto, therefore, green laser radiation has often been generated by laser radiation in the infrared spectral range being frequency-doubled by means of nonlinear-optical crystals. This is associated with a comparatively high outlay in respect of alignment and assembly. Additional factors include the costs for such crystals and comparatively low conversion efficiencies.